Hi Susan,
I think the issue you had was the caching because of the SG Optimizer plugin.
So disabled 2 plugins and was able to upload the images for the testimonials.
I did it for all 3.
When developing a site you must disable all caching because when you make a change on the site you won’t see if reflected on the front-end until you clear the cache.
If you need further help, let me know.
